- (NSData *)DESDecrypt:(NSData *)data WithKey:(NSString *)key encryptOrDecrypt:(CCOperation)encryptOperation
{
char keyPtr[kCCKeySizeAES256+1];
bzero(keyPtr, sizeof(keyPtr));
[key getCString:keyPtr maxLength:sizeof(keyPtr) encoding:NSUTF8StringEncoding];
NSUInteger dataLength = [data length];
// size_t bufferSize = dataLength + kCCBlockSizeDES;
size_t bufferSize = (dataLength + kCCBlockSizeDES) & ~(kCCBlockSizeDES - 1);
// unsigned char buffer[(bufferSize * sizeof(char))];
// memset(buffer, 0, sizeof(char));
void *buffer = malloc(bufferSize * sizeof(char));
size_t numBytesDecrypted = 0;
CCCryptorStatus cryptStatus = CCCrypt(encryptOperation, kCCAlgorithmDES,
kCCOptionPKCS7Padding,
keyPtr, kCCBlockSizeDES,
NULL,
[data bytes], dataLength,
buffer, bufferSize,
&numBytesDecrypted);
// | kCCOptionECBMode
if (cryptStatus == kCCSuccess) {
return [NSData dataWithBytesNoCopy:buffer length:numBytesDecrypted];
}
free(buffer);
return nil;
}
通過測試發現:kCCOptionPKCS7Padding與PKCS5Padding加密完成後的nsdata串時一樣的,因此判斷它們的填充方式是一樣的。
測試例子在http://www.dnspod.cn/httpdns.guide下,接口API文檔<<D+企業加密版本使用說明>>